Bo Yu,Fanming Meng,Muhammad Wasim Khan,Rui Qin,Xingbin Liu
Herein, TiO 2 /g-C 3 N 4 /Ag (TCA) composites were successfully fabricated by a simple two-step method and wet chemical reduction. Titanium isopropoxide and melamine were used as precursors to prepare TiO 2 /g-C 3 N 4 heterojunction composites by simple stirring and calcining. Then, different mass fractions of AgNPs were decorated on the surface of the above composites by wet chemical reduction to obtain a sequence of TiO 2 /g-C 3 N 4 /Ag (TCA) composites. TCA composites were analyzed by XRD, TEM, HRTEM, EDS, XPS, BET, Raman spectroscopy, PL spectrum and UV–vis diffuse reflectance spectrum. The results showed that TCA composites had remarkable enhancement in the separation of photogenerated carriers and the utilization of light, which was as result of the coordination of the three components. For photodegradation of RhB or phenol under simulated sunlight, TCA-1 samples revealed the best photocatalytic degradation performance, and the corresponding degradation rates were 91.4% at 60 min and 90.0% at 120 min, respectively. Moreover, TCA-1 composites maintained superior degradation performance after reusability tests, indicating that TCA-1 composites had excellent photochemical stability. For experimental results, a possible photodegradation mechanism of TCA composites was also proposed.
An ultra-sensitive SERS (surface-enhanced Raman scattering) substrate was fabricated orderly by depositing 360 nm Ag film on the surface of V-shaped AAO (anodized aluminum oxide), utilizing NaOH solution to remove the AAO template, the neat volcano-like Ag arrays substrate (N-V-Ag) was obtained, and then depositing 1.5, 6 and 10 nm Ag film on the surface of the N-V-Ag to obtain the AgNPs decorated volcano-like Ag arrays substrates (AgNPs-V-Ag-1.5, AgNPs-V-Ag-6 and AgNPs-V-Ag-10, respectively). Experimental results indicated that the cavity resonance mode (super-radiant bright modes) and the rim mode as well as “NP mode” (subradiant dark mode) have strong interferences, which results in a significant change in the distribution of the hot spots in the cavity compared with the N-V-Ag. The analytical enhancement factor (AEF) of AgNPs-V-Ag could reach up to 1.5 × 1011, improved by 5 orders of magnitude compared with the N-V-Ag. This novel substrate could obtain extremely low limits of detection (LOD) of 10−13 mol/L (-13 M) for Rhodamine 6G (R6G).
危险品化学品经营许可证（带存储）